Current diverter ring

ABSTRACT

The current diverter rings and bearing isolators serve to dissipate an electrical charge from a rotating piece of equipment to ground, such as from a motor shaft to a motor housing. One embodiment of the current diverter is substantially arc shaped with a plurality of radial channels extending there through. A conductive assembly may be positioned in each radial channel such that a contact portion of the conductive assembly is positioned adjacent a shaft passing through the center of the current diverter ring. The arc-shaped body may be particularly useful during installation over certain existing shafts.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application is a continuation-in-part of and claims priorityfrom U.S. patent application Ser. No. 13/089,017 filed on Apr. 18, 2011,and the present application also claims priority from provisional U.S.Pat. App. No. 61/568,265 filed on Dec. 8, 2011, both of which areincorporated by reference herein in their entireties.

FIELD OF THE INVENTION

The present invention relates to an electrical charge dissipatingdevice, and more particularly to a current Diverter Ring™ for directingelectrostatic charge to ground, which electrostatic charge is createdthrough the use of rotating equipment.

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

No federal funds were used to develop or create the invention disclosedand described in the patent application.

REFERENCE TO SEQUENCE LISTING, A TABLE, OR A COMPUTER PROGRAM LISTINGCOMPACT DISK APPENDIX

Not Applicable

AUTHORIZATION PURSUANT TO 37 C.F.R. §1.171 (d)

A portion of the disclosure of this patent document may contain materialthat is subject to copyright and trademark protection. The copyrightowner has no objection to the facsimile reproduction by anyone of thepatent document or the patent disclosure, as it appears in the Patentand Trademark Office patent file or records, but otherwise reserves allcopyrights whatsoever. CDR and Current Diverter Ring are the exclusivetrademarks of Assignee, Inpro/Seal LLC.

BACKGROUND OF THE INVENTION

Adequate maintenance of rotating equipment, particularly electricmotors, is difficult to obtain because of extreme equipment duty cycles,the lessening of service factors, design, and the lack of spare rotatingequipment in most processing plants. This is especially true of electricmotors, machine tool spindles, wet end paper machine rolls, aluminumrolling mills, steam quench pumps, and other equipment utilizing extremecontamination affecting lubrication.

Various forms of shaft sealing devices have been utilized to try toprotect the integrity of the bearing environment. These devices includerubber lip seals, clearance labyrinth seals, and attraction magneticseals. Lip seals or other contacting shaft seals often quickly wear to astate of failure and are also known to permit excessive amounts ofmoisture and other contaminants to immigrate into the oil reservoir ofthe operating equipment even before failure has exposed the interfacebetween the rotor and the stator to the contaminants or lubricants atthe radial extremity of the seal. The problems of bearing failure anddamage as applied to electrical motors using variable frequency drives(VFDs) is compounded because of the very nature of the control ofelectricity connected to VFD controlled motors.

VFDs regulate the speed of a motor by converting sinusoidal linealternating current (AC) voltage to direct current (DC) voltage, thenback to a pulse width modulated (PWM) AC voltage of variable frequency.The switching frequency of these pulses ranges from 1 kHz up to 20 kHzand is referred to as the “carrier frequency.” The ratio of change involtage to the change in time (ΔV/ΔT) creates what has been described asa parasitic capacitance between the motor stator and the rotor, whichinduces a voltage on the rotor shaft. If the voltage induced on theshaft, which is referred to as “common mode voltage” or “shaft voltage,”builds up to a sufficient level, it can discharge to ground through thebearings. Current that finds its way to ground through the motorbearings in this manner is called “bearing current.”¹ ¹http//www.greenheck.com/technical/tech_detail.php?display=files/Product_guide/fa11_(—)03

There are many causes of bearing current including voltage pulseovershoot in the WI), non-symmetry of the motor's magnetic circuit,supply imbalances, and transient conditions, among other causes. Any ofthese conditions may occur independently or simultaneously to createbearing currents from the motor shaft.² ²http//www.greenheck.com/technical/tech_detail.php?display=files/Product_guide/fa117_(—)03

Shaft voltage accumulates on the rotor until it exceeds the dielectriccapacity of the motor bearing lubricant, at which point the voltagedischarges in a short pulse to ground through the bearing. Afterdischarge, voltage again accumulates on the shaft and the cycle repeatsitself. This random and frequent discharging has an electric dischargemachining (EDM) eta which causes pitting of the bearing's rollingelements and raceways. Initially, these discharges create a “frosted” or“sandblasted” effect on surfaces. Over time, this deterioration causes agroove pattern in the bearing race called “fluting,” which is anindication that the bearing has sustained severe damage. Eventually, thedeterioration will lead to complete bearing failure.³ Seewww.Greenheck.com

The prior art teaches numerous methods of mitigating the damage shaftvoltages cause, including using a shielded cable, grounding the shaft,insulated bearings, and installation of a Faraday shield. For example,U.S. Pat. No. 7,193,836 discloses devices for controlling shaft current,which devices are designed to induce ionization in the presence of anelectrical field.

Most external applications add to costs, complexity, and exposure toexternal environmental factors. Insulated bearings provide an internalsolution by eliminating the path to ground through the bearing forcurrent to flow. However, installing insulated bearings does noteliminate the shaft voltage, which will continue to find the lowestimpedance path to ground. Thus, insulated bearings are not effective ifthe impedance path is through the driven load. Therefore, the prior artdoes not teach an internal, low-wearing method or apparatus toefficaciously ground shaft voltage and avoid electric dischargemachining of bearings leading to premature bearing failure.

SUMMARY OF THE INVENTION

An objective of the current diverter ring is to provide an improvementto seals or bearing isolators to prevent leakage of lubricant and entryof contaminants by encompassing the stator within the rotor to create anaxially directed interface at the radial extremity of the rotor. It isalso an objective of the current diverter ring to disclose and claim anapparatus for rotating equipment that conducts and transmits and directsaccumulated bearing current to ground.

It is another objective of the bearing isolator as disclosed and claimedherein to facilitate placement of a current diverter ring within thestator of the bearing isolator. Conductive segments may be positionedwithin the current diverter ring. These conductive segments may beconstructed of metallic or non-metallic solids, machined or molded.Although any type of material compatible with operating conditions andmetallurgy may be selected, bronze, gold, carbon, or aluminum arebelieved to be preferred materials because of increased conductivity,strength, corrosion and wear resistance.

It has been found that a bearing isolator having a rotor and statormanufactured from bronze has improved electrical charge dissipationqualities. The preferred bronze metallurgy is that meeting specification932 (also referred to as 932000 or “bearing bronze”). This bronze ispreferred for bearings and bearing isolators because it has excellentload capacity and antifriction qualities. This bearing bronze alloy alsohas good machining characteristics and resists many chemicals. It isbelieved that the specified bronze offers increased shaft voltagecollection properties comparable to the ubiquitous lightning rod due tothe relatively low electrical resistivity (85.9 ohms-cmil/ft @ 68 F or14.29 microhm-cm @ 20 C) and high electrical conductivity (12% IACS @ 68F or 0.07 MegaSiemens/cm @ 20 C) of the material selected.

It is another object of the current diverter ring and bearing isolatorto improve the electrical charge dissipation characteristics from thosedisplayed by shaft brushes typically mounted external of the motorhousing. Previous tests of a combination bearing isolator with aconcentric current diverter ring fixedly mounted within the bearingisolator have shown substantial reduction in shaft voltage and attendantelectrostatic discharge machining. Direct seating between the currentdiverter ring and the bearing isolator improves the conduction to groundover a simple housing in combination with a conduction member as taughtby the prior art. Those practiced in the arts will understand that thisimprovement requires the electric motor base to be grounded, as is thenorm.

It is therefore an objective of the current diverter ring and bearingisolator to disclose and claim an electric motor for rotating equipmenthaving a bearing isolator that retains lubricants, preventscontamination, and conducts and transmits bearing current to ground.

It is another objective of the current diverter ring and bearingisolator to provide a bearing isolator for rotating equipment thatretains lubricants, prevents contamination and conducts electrostaticdischarge (shaft voltage) to improve bearing operating life.

It is another objective of the current diverter ring to provide aneffective apparatus to direct electrical charges from a shaft to a motorhousing and prevent the electrical charge from passing to ground throughthe bearing(s).

Other objects, advantages and embodiments of the current diverter ringand bearing isolator will become apparent upon the reading the followingdetailed description and upon reference to drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

in order that the advantages of the invention will be readilyunderstood, a more particular description of the invention brieflydescribed above will be rendered by reference to specific embodimentsillustrated in the appended drawings. Understanding that these drawingsdepict only typical embodiments of the invention and are not thereforeto be considered limited of its scope, the invention will be describedand explained with additional specificity and detail through the use ofthe accompanying drawings.

FIG. 1 is a perspective view of one embodiment of an electric motor withwhich the current diverter ring may be employed.

FIG. 2 is a perspective cross-sectional view of a bearing isolatorwherein a portion of the stator is fashioned as a current diverter ring.

FIG. 3 is a cross-sectional view of a bearing isolator configured toaccept a current diverter ring within the stator portion of the bearingisolator.

FIG. 4 is a perspective view of the first embodiment of the currentdiverter ring.

FIG. 5 is an axial view of the first embodiment of the current diverterring.

FIG. 6 is a cross-sectional view of the first embodiment of the currentdiverter ring.

FIG. 7 is a perspective, exploded view of a second embodiment of thecurrent diverter ring.

FIG. 8A is a perspective view of a second embodiment of the currentdiverter ring assembled.

FIG. 8B is a perspective view of a second embodiment of the currentdiverter ring assembled with mounting clips.

FIG. 9 is a detailed perspective view of one embodiment of an inner bodyfor use with the second embodiment of the current diverter ring.

FIG. 10A is an axial view of one embodiment of an inner body for usewith the second embodiment of the current diverter ring.

FIG. 10B is a cross-sectional view of one embodiment of an inner bodyfor use with the second embodiment of the current diverter ring.

FIG. 11 is a cross-sectional view of one embodiment of an inner body foruse with the second embodiment of the current diverter ring withconductive fibers positioned therein.

FIG. 12 is a detailed perspective view of one embodiment of an outerbody for use with the second embodiment of the current diverter ring.

FIG. 13A is an axial view of one embodiment of an outer body for usewith the second embodiment of the current diverter ring.

FIG. 13B is a cross-sectional view of one embodiment of an outer bodyfor use with the second embodiment of the current diverter ring.

FIG. 14A is an axial view of the second embodiment of the currentdiverter ring assembled.

FIG. 14B is a cross-sectional view of the second embodiment of thecurrent diverter ring assembled.

FIG. 15A is a perspective view of a third embodiment of the currentdiverter ring.

FIG. 15B is an axial cross section view of the third embodiment of thecurrent diverter ring.

FIG. 15C is a perspective view of one embodiment of a conductiveassembly that may be used with certain embodiments of the CDR.

FIG. 16A is a perspective view of a fourth embodiment of the currentdiverter ring.

FIG. 16B is a perspective, exploded view of the fourth embodiment of thecurrent diverter ring.

FIG. 16C is an axial cross section view of the fourth embodiment of thecurrent diverter ring.

FIG. 16D is a partially enlarged view of FIG. 16, with a portion of theconductive segments hidden.

FIG. 17A is a perspective view of a fifth embodiment of the currentdiverter ring having a split design.

FIG. 17B is a perspective, exploded view of the fifth embodiment of thecurrent diverter ring.

FIG. 17C is an axial cross section view of the fifth embodiment of thecurrent diverter ring.

FIG. 17D is a detailed cross section view of the fifth embodiment of thecurrent diverter ring.

FIG. 18A is a perspective view of one embodiment of an adaptable currentdiverter ring.

FIG. 18B is an axial cross section view of one embodiment of anadaptable current diverter ring.

FIG. 19A is a perspective view of one embodiment of an arc CDR.

FIG. 19B is an axial cross section view of the embodiment of an arc CDRshown in FIG. 19A.

FIG. 19C is an axial-face view of the embodiment of an arc CDR shown inFIGS. 19A & 19B.

FIG. 20A is a perspective view of a second embodiment of an arc CDR.

FIG. 20B is an axial cross section view of the embodiment of an arc CDRshown in FIG. 20A.

FIG. 20C is an axial-face view of the embodiment of an arc CDR shown inFIGS. 20A & 20B.

DETAILED DESCRIPTION-ELEMENT LIST Description Element No. Bearingisolator 10 Bearing 12 Shaft 14 Equipment housing 16 Sealing member 17O-ring 18 Stator 20 Stator main body 22 Stator radial exterior surface23 Receptor groove 24 Stator axial projection 26 Stator radialprojection 28 Stator axial groove 29 Rotor 30 Rotor main body 32 Rotoraxial exterior surface 33 First axial interface gap  34a First radialinterface gap  34b Rotor axial projection 36 Rotor radial projection 38Rotor axial groove 39 Current diverter ring ™ (CDR ®) 40 CDR body 41Annular channel 42 First wall 43 Second wall 44 CDR radial exteriorsurface 45 Conductive segment 46 CDR main aperture 48 Inner body 50Radial channel 52 Catch  52a Mounting aperture 54 Ridge (locking) 56Inner body main aperture 58 Outer body 60 Base 62 Annular groove 64First annular shoulder  65a Second annular shoulder  65b Radialprojection 66 Outer body main aperture 68 Strap 70 Fastener 72 RadialCDR 80 Arc CDR  80a Arc cut out 81 Radial channel 82 Radial channelshelf 83 Radial exterior surface  85a Radial interior surface  85bConductive assembly 86 Binder  86a Contact portion  86b Plug 87 Mainaperture 88 Multi-ring CDR 100 Retainer 110 Retainer base 111 Firstannular groove  112a Second annular groove  112b Third annular groove 112c Fourth annular groove  112d Snap groove 113 Retainer wall 114Retainer radial exterior surface 115 Conductive segment 116 Retainermain aperture 118 Ring 120 Radial channel 122 Catch  122a Ring radialexterior surface 125 Ridge 126 Interior axial surface  127a Exterioraxial surface  127b Ring main aperture 128 Split ring segment 130Backing ring 140 Alignment pin 141 Alignment pin receptor 142 Fastenerbore 143 Fastener receptor 144 O-ring channel 145 Aperture 146 Backingring fastener 148 Adaptable CDR 160 Slot 161 Radial channel 162 Radialchannel shelf 163 Recess 164 Radial exterior surface  165a Radialinterior surface  165b Cut out 166 Main aperture 168

DETAILED DESCRIPTION

Before the various embodiments of the present invention are explained indetail, it is to be understood that the invention is not limited in itsapplication to the details of construction and the arrangements ofcomponents set forth in the following description or illustrated in thedrawings. The invention is capable of other embodiments and of beingpracticed or of being carried out in various ways. Also, it is to beunderstood that phraseology and terminology used herein with referenceto device or element orientation (such as, for example, terms like“front”, “back”, “up”, “down”, “top”, “bottom”, and the like) are onlyused to simplify description of the present invention, and do not aloneindicate or imply that the device or element referred to must have aparticular orientation. In addition, terms such as “first”, “second”,and “third” are used herein and in the appended claims for purposes ofdescription and are not intended to indicate or imply relativeimportance or significance. Additionally, the terms CDR 40, radial CDR80, multi-ring CDR 100, and adaptable CDR 160 may be usedinterchangeably when referring to generalities of configuration with abearing isolator 10, methods and/or materials of construction, and/orother general features unless explicitly stated otherwise.

One embodiment of an equipment housing 16 with which the CDR® 40 may beused is shown in FIG. 1. The CDR 40 may be press-fit into an aperture inthe equipment housing 16, or it may be secured to the exterior of theequipment housing 16 using straps 70 and fasteners 72 as described indetail below and as shown in FIG. 1. The CDR 40 may also be secured toan equipment housing 12 via other structures and/or methods, such aschemical adhesion, welding, rivets, or any other structure and/or methodsuitable for the particular application. The CDR 40 may also beconfigured to be engaged with a bearing isolator 10, or integrallyformed with a bearing isolator 10, as described in detail below.

FIG. 2 illustrates a perspective view of one embodiment of a bearingisolator 10 configured to discharge electrical impulses from the shaft14 through the equipment housing 16. The bearing isolator 10 as shown inFIG. 2 may be mounted to a rotatable shaft 10 on either one or bothsides of the equipment housing 16. The bearing isolator 10 may beflange-mounted, press-fit (as shown in FIG. 2), or attached to theequipment housing 16 using any other method and/or structure suitablefor the particular application, as was described above for the CDR 40.In some embodiments, set screws (not shown) or other structures and/ormethods may be used to mount either the stator 20 to the equipmenthousing 16 or the rotor 30 to the shaft 14. In another embodiment notpictured herein, the shaft 14 is stationary and the equipment housing 16or other structure to which the bearing isolator 10 is mounted mayrotate.

First Embodiment of a Single-Piece CDR and Bearing Isolator

In another embodiment, the CDR 40 and/or bearing isolator 10 may bemounted such that either the CDR 40 and/or bearing isolator 10 areallowed to float in one or more directions. For example, in oneembodiment a portion of the bearing isolator 10 is positioned in anenclosure. The enclosure is fashioned as two opposing plates with mainapertures therein, through which main apertures the shaft passes 14. Theinterior of the enclosure is fashioned such that the bearing isolator 10and/or CDR 40 is positioned within a truncated circle (i.e.,pill-shaped) recess on the interior of the enclosure. The contact pointsbetween the bearing isolator 10 and/or CDR 40 and the enclosure may beformed with a low friction substance, such as Teflon®, affixed thereto.

A more detailed cross-sectional view of one embodiment of a bearingisolator 10 with which the CDR 40 may be used is shown in FIG. 3. Thebearing isolator 10 shown in FIGS. 2 and 3 includes a stator 20 and arotor 30, and is commonly referred to as a labyrinth seal. Generally,labyrinth seals are well known to those skilled in the art and includethose disclosed in U.S. Pat. Nos. 7,396,017; 7,090,403; 6,419,233;6,234,489; 6,182,972; and 5,951,020; and U.S. Pat. App. Pub. No.2007/0138748, all of which are incorporated by reference herein in theirentireties, The stator 20 may be generally comprised of a stator mainbody 22 and various axial and/or radial projections extending therefromand/or various axial and/or radial grooves configured therein, which aredescribed in more detail below. In the embodiment shown in FIGS. 2 and3, the stator 20 is fixedly mounted to an equipment housing 16 with anO-ring 18 forming a seal therebetween.

The rotor 30 may be generally comprised of a rotor main body 32 andvarious axial and/or radial projections extending therefrom and/orvarious axial and/or radial grooves configured therein, which aredescribed in more detail below. In the embodiment shown, one statoraxial projection 26 cooperates with a rotor axial groove 39, and onerotor axial projection 36 cooperates with a stator axial groove 29 toform a labyrinth passage between the interior portion of the bearingisolator 10 and the external environment. The rotor 30 may be fixedlymounted to a shaft 14 and rotatable therewith. An O-ring 18 may be usedto form a seal therebetween. A sealing member 17 may be positionedbetween the stator 20 and rotor 30 on an interior interface therebetweento aide in prevention of contaminants entering the interior of thebearing isolator 10 from the external environment while simultaneouslyaiding in retention of lubricants in the interior of the bearingisolator 10.

In the embodiment of the bearing isolator 10 shown in FIGS. 2 and 3, onestator radial projection 28 provides an exterior groove in the stator 20for collection of contaminants. A first axial interface gap 34 a may beformed between the radially exterior surface of a stator radialprojection 28 and the radially interior surface of a rotor radialprojection 38. A first radial interface gap 34 h may be formed betweenthe axially exterior surface of a stator axial projection 26 and theaxially interior surface of a rotor axial groove 39. A rotor axialprojection 36 formed with a rotor radial projection 38 may be configuredto fit within a stator axial groove 29 to provide another axialinterface gap between the stator 20 and the rotor 30.

In the embodiment of a bearing isolator 10 pictured herein, one rotorradial projection 38 (adjacent the rotor axial exterior surface 33)extends radially beyond the major diameter of the stator axialprojection 26. This permits the rotor 30 to encompass the stator axialprojection 26. As is fully described in U.S. Pat. No. 6,419,233, whichis incorporated by reference herein in its entirety, this radialextension is a key design feature of the bearing isolator 10 shownherein. The axial orientation of the first axial interface gap 34 acontrols entrance of contaminants into the bearing isolator 10.Reduction or elimination of contaminants improves the longevity andperformance of the bearing isolator 10, bearing 12, and conductivesegment(s) 46. The opening of the first axial interface gap 34 a facesrearward, toward the equipment housing 16 and away from the contaminantstream. The contaminant or cooling stream will normally be directedalong the axis of the shaft 14 and toward the equipment housing 16.

To facilitate the discharge of electric energy on or adjacent the shaft14, the bearing isolator 10 may include at least one conductive segment46 positioned within the stator 20. The stator 20 may be configured witha conductive segment retention chamber adjacent the bearing 12, in whichconductive segment retention chamber the conductive segment 46 may bepositioned and secured such that the conductive segment 46 is in contactwith the shaft 14. As electrical charges accumulate on the shaft 14, theconductive segment 46 serves to dissipate those charges through thebearing isolator 10 and to the equipment housing 16. The specific sizeand configuration of the conductive segment retention chamber willdepend on the application of the bearing isolator 10 and the type andsize of each conductive segment 46. Accordingly, the size andconfiguration of the conductive segment annular channel is in no waylimiting.

Configuring the conductive segment retention chamber as an annularchannel it is not preferred. This configuration results in difficultiesrelating to, among other things, performance and manufacturing. Apreferred configuration of the conductive segment retention chamber is aradial channel 52, such as those described for the CDR 40 embodimentshown in FIGS. 7-14 or as described for the radial CDR 80, shown inFIGS. 15A-15C.

In the embodiment pictured herein, the bearing isolator 10 is formedwith a receptor groove 24. The receptor groove 24 may be fashioned onthe inboard side of the bearing isolator 10 adjacent the shaft 14, asbest shown in FIG. 3. Generally, the receptor groove 24 facilitates theplacement of a CDR 40 within the bearing isolator 10. However, otherstructures may be positioned within the receptor groove 24 depending onthe specific application of the bearing isolator 10.

As shown and described, the bearing isolator 10 in FIGS. 2 and 3includes a plurality of radial and axial interface passages between thestator 20 and the rotor 30 resulting from the cooperation of the statorprojections 26, 28 with rotor grooves 39 and the cooperation of rotorprojections 36, 38 with stator grooves 29. An infinite number ofconfigurations and/or orientations of the various projections andgrooves exist, and therefore the configuration and/or orientation of thevarious projections and grooves in the stator 20 and/or rotor 30 are inno way limiting. The bearing isolator 10 as disclosed herein may be usedwith any configuration stator 20 and/or rotor 30 wherein the stator 20may be configured with a conductive segment retention chamber forretaining at least one conductive segment 46 therein or a receptorgroove 24 as described in detail below.

A first embodiment of a current diverter ring (CDR) 40 is shown inperspective in FIG. 4, and FIG. 5 provides an axial view thereof. TheCDR 40 may be used with any rotating equipment that has a tendency toaccumulate an electrical charge on a portion thereof, such as electricalmotors, gearboxes, bearings, or any other such equipment. The firstembodiment of the CDR 40 is designed to be positioned between anequipment housing 16 and a shaft 14 protruding from the equipmenthousing 16 and rotatable with respect thereto.

Generally, the CDR 40 is comprised of a CDR body 41, which may befixedly mounted to the equipment housing 16. In the first embodiment, afirst wall 43 and a second wall 44 extend from the CDR body 41 anddefine an annular channel 42. At least one conductive segment 46 isfixedly retained in the annular channel 42 so that the conductivesegment 46 is in contact with the shaft 14 so as to create a lowimpedance path from the shaft 14 to the equipment housing 16.

A cross-sectional view of the first embodiment of the CDR 40 is shown inFIG. 6. As shown in FIG. 6, the axial thickness of the first wall 43 isless than that of the second wall 44. In the first embodiment, theconductive segment 46 is retained within the annular channel 42 by firstpositioning the conductive segment 46 within the annular channel 42 andthen deforming the first wall 43 to reduce the clearance between thedistal ends of the first and second walls 43, 44. Deforming the firstwall 43 in this manner retains the conductive segment 46 within theannular channel 42. Depending on the material used for constructing theconductive segment 46, the deformation of the first wall 43 may compressa portion of the conductive segment 46 to further secure the position ofthe conductive segment 46 with respect to the shaft 14.

A detailed view of the CDR radial exterior surface 45 is shown in FIG.6. The CDR radial exterior surface 45 may be configured with a slightangle in the axial dimension so that the CDR 40 may be press-fit intothe equipment housing 16. In the first embodiment, the angle is onedegree, but may be more or less in other embodiments not picturedherein. Also, in the first embodiment the first wall 43 is positionedadjacent the bearing 12 when the CDR 40 is installed in an equipmenthousing 16. However, in other embodiments not shown herein, the secondwall 44 may be positioned adjacent the bearing 12 when the CDR 40 isinstalled in an equipment housing 16, in which case the angle of the CDRradial exterior surface 45 would be opposite of that shown in FIG. 6.The optimal dimensions/orientation of the CDR body 41, annular channel42, first wall 43, second wall 44, and CDR radial exterior surface 45will vary depending on the specific application of the CDR 40 and aretherefore in no way limiting to the scope of the CDR 40.

As was true for the bearing isolator 10, a CDR 40 with a conductivesegment retention chamber configured as an annular channel is notpreferred. Performance and manufacturing considerations are among thereasons such a configuration is not preferred. Instead, the otherembodiments of the CDR disclosed herein, which do not have an annularchannel 42 and the attending difficulties, are preferred.

In other embodiments of the CDR 40 described in detail below, the CDR 40is mounted to the equipment housing 16 using mounting apertures 54,straps 70, and fasteners 72 fashioned in either the CDR 40 or equipmenthousing 16. The CDR 40 may be mounted to the equipment housing 16 by anymethod using any structure suitable for the particular applicationwithout departing from the spirit and scope of the CDR 40.

In the embodiment of the CDR 40 shown in FIGS. 4 and 5, three conductivesegments 46 are positioned within the annular channel 42. The optimalnumber of conductive segments 46 and the size and/or shape of eachconductive segment 46 will vary depending on the application of the CDR40, and is therefore in no way limiting. The optimal total length of allconductive segments 46 and the total surface area of the conductivesegments 46 that are in contact with the shaft 14 will vary from oneapplication to the next, and is therefore in no way limiting to thescope of the CDR 40 or of a bearing isolator 10 configured withconductive segments 46 (such as the bearing isolator shown in FIGS. 2and 3).

In the embodiment shown in FIGS. 4-6, the CDR 40 may be sized to beengaged with a bearing isolator 10 having a receptor groove 24, such asthe bearing isolator 40 shown in FIGS. 2 and 3. As described above,FIGS. 2 and 3 shown one embodiment of a bearing isolator 10 fashioned toengage a CDR 40. The receptor groove 24 may be formed as a recess in thestator 20 that is sized and shaped to accept a CDR 40 similar to the oneshown in FIGS. 4-6, or other embodiments of the CDR 40 disclosed herein.The CDR 40 may be press-fit into the receptor groove 24, or it may beaffixed to the stator 20 by any other method or structure that isoperable to fixedly mount the CDR 40 to the stator 20, including hut notlimited to set screws, welding, etc. When the CDR 40 is properly engagedwith the receptor groove 24 in the stator 20, the CDR radial exteriorsurface 45 abuts and contacts the interior surface of the receptorgroove 24.

In any of the embodiments of the CDR 40 or bearing isolator 10 employingconductive segments 46, the conductive segment 46 may be constructed ofcarbon, which is conductive and naturally lubricious. In one embodiment,the conductive segment 46 is constructed of a carbon mesh manufacturedby Chesterton and designated 477-1. In other embodiments the conductivesegment 46 has no coating on the exterior of the carbon mesh. When meshor woven materials are used to construct the conductive segments 46,often the surface of the conductive segment 46 that contacts the shaft14 becomes frayed or uneven, which may be a desirable quality to reducerotational friction in certain applications. Shortly after the shaft 14has been rotating with respect to the conductive segments 46, certainembodiments of the conductive segments 46 will wear and abrade from thesurface of the shaft 14 so that friction between the conductive segments46 and the shaft 14 is minimized. The conductive segments 46 may befibrous, solid, or other material without limitation.

In general, it is desirable to ensure that the impedance from the shaft14 to the equipment housing 16 is in the range of 0.2 to 10 ohms toensure that electrical charges that have accumulated on the shaft 14 aredischarged through the equipment housing 16 and to the base of the motor(not shown) rather than through the bearing(s) 12. The impedance fromthe shaft 14 to the equipment housing 16 may be decreased by ensuringthe fit between the bearing isolator 10 and equipment housing 16,bearing isolator 10 and CDR 40, and/or CDR 40 and equipment housing 16has a small tolerance. Accordingly, the smaller the gap between thebearing isolator 10 and equipment housing 16, bearing isolator 10 andCDR 40, and/or CDR 40 and equipment housing 16, the tower the impedancefrom the shaft 14 to the equipment housing 16.

In other embodiments not pictured herein, conductive filaments (notshown) may be affixed to either the CDR, 40 or bearing isolator 10 orembedded in conductive segments 46 affixed to either the CDR 40 orbearing isolator 10. Such filaments may be constructed of aluminum,copper, gold, carbon, conductive polymers, conductive elastomers, or anyother conductive material possessing the proper conductivity for thespecific application. Any material that is sufficiently lubricious andwith sufficiently low impedance may be used for the conductivesegment(s) 46 in the CDR 40 and/or bearing isolator 10.

In another embodiment of the CDR 40 not pictured herein, the CDR 40 isaffixed to the shaft 14 and rotates therewith. The first and secondwalls 43, 44 of the CDR 40 extend from the shaft 14, and the CDR mainbody 41 is adjacent the shaft 14. The centrifugal force of the rotationof the shaft 14 causes the conductive segments 46 and/or conductivefilaments to expand radially as the shaft 14 rotates. This expansionallows the conductive segments 46 and/or filaments to make contact withthe equipment housing 16 even if grease or other contaminants and/orlubricants (which increase impedance and therefore decrease the abilityof the CDR 40 to dissipate electrical charges from the shaft 14 to theequipment housing 16) have collected in an area between the CDR 40 andthe equipment housing 16.

In another embodiment not pictured herein, a conductive sleeve (notshown) may be positioned on the shaft 14. This embodiment is especiallyuseful for a shaft 14 having a worn or uneven surface that wouldotherwise lead to excessive wear of the conductive segments 46. Theconductive sleeve (not shown) may be constructed of any electricallyconductive material that is suitable for the particular application, andthe conductive sleeve (not shown) may also be fashioned with a smoothradial exterior surface. The conductive sleeve (not shown) would thenserve to conductive electrical charges from the shaft 14 to theconductive segments 46 in either the CDR 40 or a bearing isolator 10.Another embodiment that may be especially useful for use with shafts 14having worn or uneven exterior surfaces is an embodiment whereinconductive filaments or wires are inserted into the conductive segments46. These conductive filaments or wires may be sacrificial and fill indepressions or other asperities of the surface of the shaft 14.

In another embodiment not pictured herein, conductive screws (not shown)made of suitable conductive materials may be inserted into theconductive segments 46. Furthermore, spring-loaded solid conductivecylinders may be positioned within the CDR 40 and/or bearing isolator 10in the radial direction so as to contact the radial exterior surface ofthe shaft 14.

Although elegant in its design, the CDR 40 shown in FIGS. 4-6 is not thepreferred embodiment of the CDR 40, as previously mentioned. Among otherconsiderations, performance and manufacturing difficulties with thisdesign dictate that other embodiments of the CDR 40 are more desirable.Particularly, the two-piece CDR 40 shown in FIGS. 7-14 and described indetail below and the radial CDR 80 shown in FIGS. 15A, 15B result inboth of those embodiments being superior to that shown in FIGS. 4-6.

Illustrative Embodiment of a Two-Piece CDR

A second embodiment of a CDR 40 is shown in FIGS. 7-14. In the secondembodiment of the CDR 40, the CDR is formed from the engagement of aninner body 50 with an outer body 60, which are shown disengaged but inrelation to one another in FIG. 7. The inner body 50 and outer body 60in the second embodiment of the CDR 40 engage one another in a snapping,interference-type fit, which is described in detail below.

A perspective view of an inner body 50, which may be generally ringshaped, is shown in FIG. 9. The inner body 50 may include at least oneradial channel 52 fashioned in an exterior face of the inner body 50,which includes a main aperture 58 through which a shaft 14 may bepositioned. The embodiment pictured in FIG. 9 includes three radialchannels 52, but other embodiments may have a greater or lesser numberof radial channels 52, and therefore the number of radial channels in noway limits the scope of the CDR 40. Each radial channel 52 may be formedwith a catch 52 a therein to more adequately secure certain types ofconductive segments 46. It is contemplated that a catch 52 a will bemost advantageous with conductive segments 46 made of a deformable orsemi-deformable material (as depicted in FIG. 14B), but a catch 52 a maybe used with conductive segments 46 constructed of materials havingdifferent mechanical properties. The radial channels 52 as shown areconfigured to open toward a shaft 14 positioned in the main aperture 58.The inner body 50 may be formed with a ridge 56 on the radial exteriorsurface thereof. The ridge 56 may be configured to engage the annulargroove 64 formed in the outer body 60 as described in detail below.

The inner body 50 may be formed with one or more mounting apertures 54therein. The embodiment shown in FIGS. 8-11 is formed with threemounting apertures 54. Mounting apertures 54 may be used to secure theCDR 40 to an equipment housing 16 or other structure as shown in FIG. 1,A strap 70 or clip my be secured to the CDR 40 using a fastener 72, suchas a screw or rivet, engaged with a mounting aperture 54, as shown inFIGS. 1 and 8B. The presence or absence of mounting apertures 54 willlargely depend on the mounting method of the CDR 40. For example, in theembodiment shown in FIGS. 14A and 14B, the inner body 50 does notinclude any mounting apertures 54. It is contemplated that suchembodiments will be optimal for use within a bearing isolator 10 and/ora CDR 40 that will be press fit into an equipment housing 16 or otherstructure.

A perspective view of an outer body 60, which also may be generally ringshaped, is shown in FIG. 12. The outer body 60 may be formed with a base62 having an annular groove 64 formed on the radial interior surfacethereof. The annular groove 64 may be defined by a first annularshoulder 64 a and a second annular shoulder 65 b, A radial projection 66may extend radially inward from the base 62 adjacent either the firstand/or second shoulder 65 a, 65 b. In the embodiment pictured, theradial projection 66 is positioned adjacent the first annular shoulder65 a and includes a main aperture 68 therein, through which a shaft 14may be positioned. The annular groove 64 may be configured such that theridge 56 formed in the inner body 50 engages the annular groove 64 so asto substantially fix the axial position of the inner body 50 withrespect to the outer body 60. As shown in FIGS. 10B, and 14B, the ridge56 may be slanted or tapered so that upon forced insertion of the innerbody 50 in the outer body 60, the ridge 56 slides past the secondannular shoulder 65 b and into the annular groove 64 to axially securethe inner body 50 and the outer body 60. The engagement between theridge 56 and the annular groove 64 thereafter resists separation ordissociation of the inner and outer bodies 50, 60. In other embodimentsnot shown herein, the ridge 56 is not limited to a taperedconfiguration. The ridge 56 and base 62 may also be configured so aninterference fit is created upon engagement to resist separation ordisassociation of the inner and outer bodies 50, 60.

As shown in FIGS. 14A and 14B, the inner body 50 and outer body 60 maybe configured so that the interior periphery of the radial projection 66has the same diameter as the interior periphery of the inner body 50 sothat both the inner and outer bodies 50, 60 have the same clearance froma shaft 14 when installed. It is contemplated that in most applicationsthe CDR 40 will be installed so that the surface shown in FIG. 14A isaxially exterior to the equipment housing 16 or other structure.However, if the CDR 40 is engaged with a bearing isolator 10, the CDR 40may be oriented such that the surface shown in FIG. 14A is facing towardthe interior of the equipment housing 16 or other structure to which thebearing isolator 10 is mounted.

As shown in FIG. 11, conductive segments 46 may be positioned in eachradial channel 52. It is contemplated that the radial channels 52 willbe fashioned in the axial surface of the inner body 50 that ispositioned adjacent the radial projection 66 of the outer body 60 whenthe CDR 40 is assembled, as shown in FIGS. 14A and 14B. This orientationsecures the axial position of the conductive segments 46. As mentionedpreviously, a CDR 40 employing radial channels 52 for retention ofconductive segments 52 is preferred as compared to a CDR 40 having anannular channel 42. Typically, but depending on the materials ofconstruction, the conductive segments 46 are sized so as to extend pastthe minor diameter of the inner body 50 into the main aperture 58 tocontact the shaft 14. The radial channels 52 are sized so as to notintersect the outer periphery of the inner body 50. This prevents theconductive segment 46 from contacting the annular groove 64 of the outerbody 60.

The bearing isolator 10 and CDR 40 may be constructed from anymachinable metal, such as stainless steel, bronze, aluminum, gold,copper, and combinations thereof, or other material having lowimpedance. The CDR 40 or bearing isolator 10 may be flange-mounted,press-fit, or attached to the equipment housing 16 by any otherstructure or method, such as through a plurality of straps 70 andfasteners 72.

In certain applications, performance of the bearing isolator 10 may beimproved by eliminating the O-rings 18 and their companion groovesfashioned in the stator 20 and the rotor 30, as shown in FIGS. 2 and 3.The high-impedance nature of material used to construct the O-ring 18(such as rubber and/or silicon) may impede conductivity between bearingisolator 10 and the equipment housing 16, thereby decreasing the overallelectrical charge dissipation performance of the bearing isolator 10.However, if the O-rings 18 may be constructed of a low-impedancematerial, they may be included in any application of the CDR 40 and/orbearing isolator 10. The optimal dimensions/orientation of the CDR 40,inner body 50, outer body 60, and various features thereof will varydepending on the specific application of the CDR 40 and are therefore inno way limiting to the scope of the CDR 40.

Second Embodiment of a Single-Piece CDR

A radial CDR 80 is another embodiment of a CDR 40, which is shown inFIGS. 15A, 15B as a ring-shaped structure having a main aperture 88 inthe center thereof. As with other embodiments of the CDR 40 disclosedherein, the CDR 40 may be mounted to rotational equipment through anystructure and/or method without limitation. The embodiment of the radialCDR 80 shown in FIGS. 15A and 15B includes three straps 70 affixed tothe radial CDR 80 via fasteners 72. Other fasteners 72 may be used tosecure the straps 70 to the rotational equipment, thereby securing theradial CDR 80 to the rotational equipment. In other embodiments of theradial CDR 80, the radial exterior surface 85 a of the radial CDR 80 ispress-fit into the rotational equipment housing 16. However, themounting method for the radial CDR is in no way limiting to its scope.

The embodiment of the radial CDR 80 shown herein includes three radialchannels 82 extending from the radial exterior surface 85 a to theradial interior surface 85 b. Each radial channel 82 may include aradial channel shelf 83, which is best shown in FIG. 15B. In thepictured embodiment, the radial channel shelf 83 is located adjacent theradial interior surface 85 b of the radial CDR 80.

A conductive assembly 86 may be configured to securely lit within theradial channel 82. One embodiment of a conductive assembly 86 is shownin detailed in FIG. 15C. The conductive assembly 86 may comprise abinder 86 a that is primarily located within the radial channel 82 and acontact portion 86 b that extends radially inward from the radialchannel 82. The binder 86 a may be formed as any structure that retainsthe elements of the conductive assembly 86, including but not limited toa chemical adhesive, structural cap or tether, or combinations thereof.Other types of conductive assemblies 86 may be used with the radial CDR80 without limitation.

The conductive assemblies 86 in the radial CDR 80 may be configured tobe replaceable. That is, once the contact portion 86 b of a conductiveassembly 86 has been exhausted, or the conductive assembly 86 shouldotherwise be replaced, the user may remove the conductive assembly 86from the radial channel 82 and insert a new conductive assembly 86therein.

Illustrative Embodiments of a Multi-Ring CDR

A first embodiment of a multi-ring CDR 100 is shown in FIGS. 16A-16D.This embodiment of a multi-ring CDR 100 is similar to the two-piece CDR40 described in detail above and shown in FIGS. 7-14B. The multi-ringCDR 100 includes a retainer 110 with which at least two rings 120 aresecured. The retainer 110 may be substantially ring-shaped with aretainer main aperture 118 in the center thereof, which retainer mainaperture 118 corresponds to each ring main aperture 128.

The retainer 110 may be formed with a plurality of annular grooves 112a, 112 b, 112 c, 112 d on the radial interior surface of the retainerbase 111 to provide seating surfaces for the various rings 120. Theembodiment of the multi-ring CDR 100 shown herein includes a total offour rings 120 and four annular grooves 112. However, other embodimentsmay be a greater or smaller number of rings 120 and correspondingannular grooves 112 without limiting the scope of the multi-ring CDR,100.

The rings 120 may be formed with a plurality of radial channels 122similar to those formed in the inner body 50 for the embodiment of theCDR 40 shown in FIGS. 7-14. The radial channel 116 is typically formedon the interior axial surface 127 a of the ring 120, A conductivesegment 116 may be positioned in each radial channel 122. Additionally,each radial channel 122 may be formed with a catch 122 a therein tobetter retain the conductive segment 116.

A retainer wall 114 may extend radially inward from the first annulargroove 112 a toward the retainer main aperture 118, which retainer wall114 is analogous to the radial projection 66 of the outer body 60 forthe CDR 40 embodiment shown in FIGS. 7-14. In the embodiments picturedherein, the retainer wall 114 is substantially perpendicular to theretainer base 111. The retainer wall 114 may serve as a stop for theinnermost ring 120 as shown in FIGS. 16C and 16D. The interior axialsurface 127 a of the innermost ring 120 my abut the retainer wall 114,thereby compressing the conductive segments 116 positioned in the radialchannels 122 of the innermost ring 120 between the ring 120 and theretainer wall 114. The ring radial exterior surface 125 of the innermostring 120 may engage the first annular groove 112 a in such a manner asto secure the innermost ring 120 to the retainer 110 via an interferencefit.

The interior axial surface 127 a of the ring 120 immediately exterior tothe innermost ring 120 may abut the exterior axial surface 127 b of theinnermost ring 120, thereby compressing the conductive segments 116positioned in the radial channels 112 of that ring 120 between that ring120 and the innermost ring 120. The ring radial exterior surface 125 ofthe ring 120 immediately exterior to the innermost ring 120 may engagethe second annular groove 112 b in such a manner as to secure that ring120 to the retainer via an interference fit. This is shown in detail inFIGS. 16C and 16D. The arrangement may continue with all rings 120engaged with the retainer 110.

The outermost ring 120 may be configured with a ridge 162 on the ringradial exterior surface 125. This ridge 162 may be angled upward fromthe interior axial surface 127 a to the exterior axial surface 127 b,such that the ridge 126 engages a snap groove 113 that may be formed inthe outermost annular groove 112 (which is the fourth annular groove 112d in the embodiment shown herein). Accordingly, the outermost ring 120may be secured to the retainer 110, thereby securing all other rings120, through the engagement of the ridge 126 with the snap groove 113.This is analogous to the engagement of the inner body 50 with the outerbody 60 via the ridge 56 and annular groove 64, respectively located onthe inner body 50 and outer body 60 for the CDR 40 shown in FIGS. 7-14.

In a split embodiment of a multi ring CDR 100, the rings 120 may besecured to the retainer 110 using fasteners, such as fasteners, as shownin FIGS. 17A-17D. The rings 120 in this embodiment may be comprised oftwo ring segments 130, and the retainer 110 may be formed as twoseparate pieces. The interaction between the innermost split ringsegments 130 and the retainer 110 is analogous to that described abovefor the first embodiment of the multi-ring CDR 100. Furthermore, theinteraction between adjacent split ring segments 130 and thecorresponding retention of conductive segments 116 for the splitmulti-ring CDR 100 is analogous to that described for the firstembodiment of the multi-ring CDR 100. To retain the split ring segments130, an interference fit between the ring radial exterior surface 125and individual annular grooves 112 a, 112 b, 112 c, 112 d in conjunctionwith a snap groove 113 in the outermost annular groove 112 and a ridge126 in the outermost ring 120. The interference fit securement mechanismmay be employed alone or in combination with a plurality of fasteners72, or the plurality of fasteners 72 may be solely employed as asecurement mechanism. If fasteners 72 are used, the ring segments 130may be formed with apertures 132 to receive the fasteners 72.

A backing ring 140 may be used with certain embodiments of the CDR 40,80, 100, as shown in FIGS. 17A-17D. The backing ring 140 may also beformed of two distinct pieces, which pieces may be secured to oneanother through a plurality of corresponding alignment pin receptors142, fastener bores 143, fastener receptors 144 and correspondingalignment pins 141 and fasteners 72. In the embodiment shown in FIG.17B, two alignment pins 141 and corresponding a alignment pin receptors142 are positioned at the seam of the backing ring 140 to properly alignthe two pieces. Two fasteners 72 may be placed in respective fastenerbores 143 so that a portion of each fastener 72 engages a respectivefastener receptor 144, thereby securing the two pieces of the backingring 140 to one another.

The backing ring 140 may be manufactured so that the gap between the twopieces is negligible so as to prevent ingress of contaminants to andegress of lubricants from the bearing location. To do this, first acircle may be bisected across its diameter. The two pieces, when joined,form an ellipse due to the material removed during cutting. Accordingly,the two pieces may be machined so that together they form a perfect ornear perfect circle. Alignment pin receptors 142 and correspondingalignment pins 141 and/or fastener bores 143 and corresponding fasteners72 may be used alone or in combination to secure the relative positionsof the two pieces (as described above) during the machining. Relativestability of the two pieces is required to create a perfect or nearperfect circle from the two pieces. At this point the backing ring mainaperture 148 and O-ring channel 145 may be fashioned in the backing ring140 to the desired specifications. Apertures 146 may be fashioned in thebacking ring 140 per the user's requirements so that the perfectly ornear perfectly circular backing ring 140 may be properly centered over ashaft or other structure.

Illustrative Embodiment of an Adaptable CDR

One embodiment of an adaptable CDR 160 is shown in FIGS. 18A and 18B.The adaptable CDR 160 is designed so that it may be mounted to a widevariety of rotational equipment with different geometries. The adaptableCDR may include a plurality of radial channels 162 that extend from theradial exterior surface 165 a to the radial interior surface 165 badjacent the main aperture 168. Like the radial channels 82 in theradial CDR 80, the radial channels 162 in the adaptable CDR 160 mayinclude a radial channel shelf 163. Accordingly, a conductive assembly86 may secured in each radial channel 162.

It is contemplated that the user will drill and tap holes in theexterior of the rotational equipment such that a fastener 72 may passthrough each of the slots 161 formed in the adaptable CDR 160. Theadaptable CDR 160 may include a plurality of recesses 164 to betteraccommodate differences in the exterior of various rotational equipment.The adaptable CDR 160 may have a cut out 166 protruding into the mainaperture 168 to facilitate installation of the adaptable CDR 160 over ashaft or other object.

Illustrative Embodiments of an Arc CDR

An arc CDR, 80 a is another embodiment of a CDR 40. A first embodimentof an arc CDR 80 a is shown in FIGS. 19A-19C as a semi-circular shapedstructure having a main aperture 88 in the center thereof and an arc cutout 81. FIG. 19A provides a perspective view of the first illustrativeembodiment of an arc CDR 80 a positioned over a shaft 14. FIG. 19Bprovides another perspective view of the first embodiment of an arc CDR80 a without a shaft 14 for purposes of clarity. FIG. 19C provides aradial cross-sectional view of the arc CDR 80 a shown in FIGS. 19A &19B. A perspective view of a second embodiment of an arc CDR 80 a shownpositioned around a shaft 14 is shown in FIG. 20A. FIG. 20B providesanother perspective view of this embodiment of an arc CDR 80 a with theshaft 14 removed in FIG. 20B, and FIG. 20C is a radial cross-sectionalview.

The illustrative embodiments of the arc CDR 80 a as shown hereinfunction substantially the same as the radial CDR 80 shown in FIGS. 15Aand 15B. However, because the arc CDR 80 a is not a full ring (which theradial CDR 80 is) the arc CDR 80 a may be easier to install over certainshafts 14 than the radial CDR 80 for specific applications in the sameway the adaptable CDR 160 (shown in FIGS. 18A and 18B) be easier toinstall than the radial CDR 80. For certain embodiments of the arc CDR80 a it may be beneficial to use a sleeve (not shown), plate (not shown)or other structure to properly position the arc CDR 80 a with respect tothe shaft 14. It is contemplated that the embodiment of an arc CDR 80 ashown in FIGS. 19A-19C may be engaged with the structure from which theshaft 14 extends via one or more mounting apertures 54 therein that maycooperate with a fastener 72. It is contemplated that the embodiment ofan arc CDR 80 a shown in FIGS. 20A-20C may be engaged with the structurefrom which the shaft 14 extends via one or more straps 70 in cooperationwith one or more fasteners 72. However, any suitable structure and/ormethod for securing the arc CDR 80 a to a structure may be used withoutlimitation.

The illustrative embodiments of an arc CDR 80 a pictured herein isconfigured such that the arc CDR 80 a extends beyond 180 degrees of acircle. More specifically, the illustrative embodiment of the arc CDR 80a is approximately 200 degrees of a full circle. However, in otherembodiments the length of the arc CDR 80 a may be greater than 200degrees of a full circle. In still other embodiments, the length of thearc CDR 80 a may be less than 180 degrees of a full circle.

The embodiment of an arc CDR 80 a shown in FIGS. 19A-19C includes threeradial channels 82 extending from the radial exterior surface 85 a tothe radial interior surface 85 b. Each radial channel 82 may include aradial channel shelf 83, which is best shown in FIG. 19C. In thepictured embodiments, the radial channel shelf 83 is located adjacentthe radial interior surface 85 b of the arc CDR 80 a. The embodiment ofan arc CDR 80 a shown in FIGS. 20A-20C includes four radial channels 82that may be so configured. A conductive assembly 86 may be configured tosecurely engage a radial channel 82, and a plug 87 may be positionedover the conductive assembly 86 to secure the position of the conductiveassembly 86. One embodiment of a conductive assembly 86 is shown indetailed in FIG. 15C. Other types of conductive assemblies 86 may beused with the arc CDR 80 a without limitation. One embodiment of a plug87 is threaded and cooperates with threads formed in a radial channel82, as shown in FIG. 19C.

The conductive assemblies 86 in the arc CDR 80 a may be configured to bereplaceable. That is, once the contact portion 86 b of a conductiveassembly 86 has been exhausted, or the conductive assembly 86 shouldotherwise be replaced, the user may remove the conductive assembly 86(and/or plug 87 if one is used) from the radial channel 82 and insert anew conductive assembly 86 therein. The number of radial channels 82formed in an arc CDR 80 a in no way limits the scope thereof, andsimilarly, the number of conductive assemblies engaged therewith in noway limits the scope of an arc CDR 80 a.

The bearing isolator 10 and/or CDR 40 employed with an equipment housing16 creates a stable, concentric system with the rotating shaft 14 as thecenter point. Inserting a CDR 40 into bearing isolator 10 such as theone shown in FIGS. 2 and 3 within the equipment housing 16 forms arelatively fixed and stable spatial relationship between the conductingelements, thereby improving the collection and conduction ofelectrostatic discharge from the shaft 14 to ground, through theconducting elements of the CDR 40 and bearing isolator 10. This improvedmotor ground sealing system directly seats major elements together,which compensates for imperfections in the shaft 14 (which may not beperfectly round) and ensures the variation or change in distance fromthe conductive segments 46 to the surface of the shaft 14 caused byexternal forces acting on the CDR 40 and/or bearing isolator 10 areminimal. This promotes effective conduction of electrical charges fromthe shaft 14 to the equipment housing 16.

Having described the preferred embodiments, other features of the CDR40, 80, 80 a, 100, 160 and disclosed bearing isolators 10 willundoubtedly occur to those versed in the art, as will numerousmodifications and alterations in the embodiments as illustrated herein,all of which may be achieved without departing from the spirit and scopeof the CDR 40, 80, 80 a, 100, 160 and/or bearing isolator 10. It shouldbe noted that the bearing isolator 10 and CDR 40, 80, 80 a, 100, 140 arenot limited to the specific embodiments pictured and described herein,but are intended to apply to all similar apparatuses and methods fordissipating an electrical charge from a shaft 14 to an equipment housing16. Modifications and alterations from the described embodiments willoccur to those skilled in the art without departure from the spirit andscope of the bearing isolator 10 and CDR 40, 80, 80 a, 100, 140.

The invention claimed is:
 1. An arc current diverter ring comprising: a.a body that is substantially arc-shaped; b. a main aperture positionedin the center of said body; c. a plurality of radial channels, whereineach said radial channel extends from the radial exterior surface ofsaid body to the radial interior surface of said body; d. a radialchannel shelf, wherein said radial channel shelf is positioned in one ofsaid radial channels adjacent the radial interior surface of said mainbody; and, e. a conductive assembly positioned in one of said radialchannels, wherein a contact portion of said conductive assemblyprotrudes from said radial channel radially inward past said radialinterior surface.
 2. The arc current diverter ring according to claim 1wherein said body is further defined as being 200 degrees of a fullcircle.
 3. The arc current diverter ring according to claim 1 whereinsaid body is further defined as being less than 180 degrees of a fullcircle.
 4. The arc current diverter ring according to claim 2 whereinsaid arc current diverter ring further comprises a plug, wherein saidplug engages said radial channel to secure the radial position of acorresponding conductive assembly.
 5. A method of dissipating electricalcurrent from a shaft, said method comprising the steps of: a. mountingan arc current diverter ring (hereinafter “arc CDR”) around a portion ofsaid shaft, wherein said arc CDR comprises: i. a body that issubstantially arc-shaped; ii. a main aperture positioned in the centerof said body; a plurality of radial channels, wherein each said radialchannel extends from the radial exterior surface of said body to theradial interior surface of said body; iv. a radial channel shelf,wherein said radial channel shelf is positioned in one of said radialchannels adjacent the radial interior surface of said main body; v. aconductive assembly positioned in one of said radial channels, wherein acontact portion of said conductive assembly protrudes from said radialchannel radially inward past said radial interior surface; b. allowingsaid contact portion of said conductive assembly to contact said shaftsuch that electricity may flow from said shaft to said conductiveassembly.
 6. The arc current diverter ring according to claim 1 whereinsaid plurality of radial channels is further defined as three radialchannels.
 7. The arc current diverter ring according to claim 1 whereinsaid plurality of radial channels is further defined as four radialchannels.
 8. The arc current diverter ring according to claim 1 whereinsaid plurality of radial channels is further defined as five radialchannels.
 9. The arc current diverter ring according to claim 1 whereinsaid plurality of radial channels is further defined as six radialchannels.
 10. The arc current diverter ring according to claim 6 whereinsaid plurality of radial channels is further defined as being equallyspaced about said body.
 11. The arc current diverter ring according toclaim 7 wherein said plurality of radial channels is further defined asbeing equally spaced about said body.
 12. The arc current diverter ringaccording to claim 8 wherein said plurality of radial channels isfurther defined as being equally spaced about said body.
 13. The arccurrent diverter ring according to claim 9 wherein said plurality ofradial channels is further defined as being equally spaced about saidbody.
 14. The arc current diverter ring according to claim 1 whereinsaid current diverter ring further comprises a plurality of conductiveassemblies corresponding to said plurality of radial channels.
 15. Thearc current diverter ring according to claim 1 wherein a radial exteriorsurface of said body is further defined as being angled in the axialdirection such that said radial current diverter ring may be securelypressed into either a receptor groove formed in a bearing isolator or anaperture formed in a motor housing.
 16. The arc current diverter ringaccording to claim 1 wherein said body further comprises a plurality ofmounting apertures positioned in an axial face thereof, and wherein aplurality of fasteners and straps cooperatively engage said plurality ofmounting apertures.
 17. The arc current diverter ring according to claim1 wherein said conductive assembly comprises a carbon-based filament.18. The arc current diverter ring according to claim 1 wherein saidconductive assembly comprises a binder and a contact portion, andwherein said contact portion extends into said main aperture.
 19. Thearc current diverter ring according to claim 1 wherein said body isfurther defined as being constructed of bronze.
 20. The arc currentdiverter ring according to claim 1 wherein said body is further definedas being positioned adjacent a body of a second radial current diverterring.